Tigthen cert_parse_ee_cert() and ta_parse()

Require that a cert fed to cert_parse_ee_cert() have an EE cert purpose.
Instead of throwing a warning for BGPsec router certs, check for the TA
purpose in ta_parse() and reject everything else.

ok job

diff --git a/usr.sbin/rpki-client/cert.c b/usr.sbin/rpki-client/cert.c
index 5cf6011..ba29b7e 100644 (file)
--- a/usr.sbin/rpki-client/cert.c
+++ b/usr.sbin/rpki-client/cert.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: cert.c,v 1.143 2024/06/08 13:31:37 tb Exp $ */
+/*     $OpenBSD: cert.c,v 1.144 2024/06/08 13:33:49 tb Exp $ */
 /*
  * Copyright (c) 2022 Theo Buehler <tb@openbsd.org>
  * Copyright (c) 2021 Job Snijders <job@openbsd.org>
@@ -747,6 +747,12 @@ cert_parse_ee_cert(const char *fn, int talid, X509 *x)
        if (!x509_cache_extensions(x, fn))
                goto out;
 
+       if ((cert->purpose = x509_get_purpose(x, fn)) != CERT_PURPOSE_EE) {
+               warnx("%s: expected EE cert, got %s", fn,
+                   purpose2str(cert->purpose));
+               goto out;
+       }
+
        if (X509_get_key_usage(x) != KU_DIGITAL_SIGNATURE) {
                warnx("%s: RFC 6487 section 4.8.4: KU must be digitalSignature",
                    fn);
@@ -1121,12 +1127,9 @@ ta_parse(const char *fn, struct cert *p, const unsigned char *pkey,
                    "trust anchor may not specify CRL resource", fn);
                goto badcert;
        }
-       /*
-        * XXX - this check for BGPsec router certs doesn't make all that much
-        * sense. Consider introducing a TA purpose for self-issued CA certs.
-        */
-       if (p->purpose == CERT_PURPOSE_BGPSEC_ROUTER) {
-               warnx("%s: BGPsec cert cannot be a trust anchor", fn);
+       if (p->purpose != CERT_PURPOSE_TA) {
+               warnx("%s: expected trust anchor purpose, got %s", fn,
+                   purpose2str(p->purpose));
                goto badcert;
        }
        /*